A similar question has cropped up a number of times on the forum. You may want to search for the threads to see what the various responses are.
As for multiple libraries... yes, you can have them and start them with command line switches, but it's not optimal. You'll have to import a new book to each library and then manage them, i.e. add/delete from each library separately.
The consensus seems to be to use tags to do what you want. You can have any tags you want. Have multiple devices? Use a tag for each one. I use a tag "Read" for the books I've already read. You can then search on tags to find those you have or haven't read by including/excluding what you want. If you have other users, such as a spouse, sibling, or child, you can have tags for each of them and then search on those tags. Tags could be "name1", "name2", "childsname", "name1-read", "name1-unread", "name1-sony", "name1-iliad", etc. Tags can then be added/removed/modified at will.
Hope this gives you some ideas
